Sipcalc is an "advanced" console based ip subnet calculator.
- IPv4
  * Multiple address and netmask input formats.
  * Retrieving of address information from interfaces.
  * Classfull and CIDR output.
  * Multiple address and netmask output formats (dotted quad, hex, number
    of bits).
  * Output of broadcast address, network class, Cisco wildcard, hosts/range,
    network range.
  * Output of multiple types of bitmaps.
  * Output of a user-defined number of extra networks.
  * Multiple networks input from commandline.
  * Parsing of a newline separated list of networks from standard input (STDIN).
  * The ability to "split" a network based on a smaller netmask, now also with
    recursive runs on the generated subnets.
  * DNS resolution.
- IPv6
  * Compressed and expanded input addresses.
  * Compressed and expanded output.
  * Standard IPv6 network output.
  * v4 in v6 output.
  * Reverse dns address generation.
  * The ability to "split" a network based on a smaller netmask, now also with
    recursive runs on the generated subnets.
  * DNS resolution.
